In order to explore the influence of loading rate on the strength and deformation characteristics of undisturbed loess and the parameters of Duncan-Chang model, the SLB-1 triaxial shear permeability tester was used to carry out the unconsolidated and undrained triaxial shear test of undisturbed loess under different confining pressures and shear rates, and verify its macroscopic mechanical properties through microscopic tests. The results show that within the setting range of the test parameters, the shear rate has a significant effect on the mechanical properties of the undisturbed loess. The deviator stress-strain relationship of the undisturbed loess under different shear rate basically conforms to the hyperbolic relationship, and the initial deformation modulus increases with the increase of confining pressure, and with the increase of shear rate, it increases first and then decreases; There is an obvious critical shear rate turning point of 1.7 mm?min-1 between the cohesive force c, dimensionless base number K, stress failure ratio Rf and failure strength. At this time, each parameter reaches the maximum value, and the dimensionless index n is no obvious rule to follow; When the shear rate is less than this critical value, the cohesion force c, the dimensionless base K, the stress-to-failure ratio Rf, and the fracture strength increase with the increases of the shear rate and decrease to a certain extent when the shear rate exceeds the critical value, and generally appear to increase first and then decrease, the internal friction angle gradually increases with the increase of the shear rate ,but the increase amplitude is little; The deviator stress-strain curve of the sample shows a strain hardening type without obvious peak point; By fitting the curve, the fitting formula between the shear strength index and the failure strength of the unmodified loess sample and the different shear rate was obtained so as to better study the influence of the changes of shear rate on the mechanical properties of Xining undisturbed loess.